Solar energy has become one of the main pillars of a sustainable and efficient home. Innovation in solar technology continues to advance and improve the performance of solar radiation collection systems. This has given rise to the passive solar systems, which allow solar energy to be harnessed through architectural elements that do not require mechanical or electrical devices, such as fans or recirculation pumps, among others. Passive solar systems use elements such as windows, roofs and walls to capture and store thermal energy, which contributes to a more efficient and environmentally friendly home.
Throughout this article, we will explain in detail the characteristics, advantages and operation of these passive solar systems, which set the standard in modern bioclimatic architecture.
What are passive solar systems?
The passive solar systems Solar systems are those that take advantage of solar radiation without the need to transform or store it using technological devices. They use architectural principles to capture, store and distribute the sun's heat naturally. The elements that form part of these systems are mainly windows, roofs, walls, interior patios, attached greenhouses, solar chimneys and galleries. These allow solar energy to enter and be distributed inside without the need to use additional technologies, as occurs in active solar systems that require devices such as photovoltaic panels.
These types of systems are designed to improve the Energy Efficiency of buildings to the maximum, taking advantage of the three heat transfer mechanisms: conduction, convection and radiationThanks to these mechanisms, the captured heat is transmitted to the interior of the buildings efficiently, achieving a warm environment in winter and avoiding overheating during the summer.
This is where the difference between passive and active solar energy lies. Passive solar energy does not require energy transformations or additional technological interventions, while active solar energy depends on devices such as solar panels or thermal collectors that transform the energy and store or distribute it.
Passive solar systems in bioclimatic homes
Bioclimatic architecture aims to maximize the energy efficiency of buildings by taking advantage of the climatic conditions of the place. passive solar systems They are an essential part of this type of architecture, as they allow solar energy to be captured and used directly, without the need for additional equipment.
A bioclimatic home takes into account the orientation and local climate to optimize solar radiation. For example, in the northern hemisphere, it is ideal to orient the main windows to the south to capture the greatest amount of sunlight in winter and avoid direct sunlight in summer. In addition, high-quality construction materials are used. thermal mass, such as brick or stone, which store heat during the day and release it gradually at night, maintaining a pleasant indoor temperature throughout the day without the need for additional heating.
The use of passive solar systems is not limited to heat capture. They also include strategies such as the use of Natural ventilation through interior patios or strategically located windows to generate air currents that cool the building in summer.
In the bioclimatic housingPassive solar systems provide a comfortable thermal environment throughout the year by using natural resources such as the sun and wind to regulate the temperature. This significantly reduces the dependence on conventional energy sources, such as fossil fuels, and contributes to reducing the carbon footprint of the building.
Capture of sunlight
To optimize the capture of sunlight, it is essential that the elements of the building are correctly oriented and designed. In passive solar systems, the windows and bay windows They play a key role in allowing solar radiation to enter interior spaces. These elements must face south (in the northern hemisphere), which ensures that solar radiation is captured in winter and prevents overheating in summer.
Other devices, such as inertia walls and attached greenhouses, allow indirect capture of solar energy. In these cases, solar radiation falls on a glass surface that acts as a heat accumulator. This heat is transferred to the interior of the building by mechanisms such as convection or thermal mass. The use of opening regulators allows the amount of heat entering the building to be controlled, adapting it to the needs of each season.
Advantages of passive solar systems
Passive solar systems offer multiple and advantages, both economically and in terms of sustainability and comfort:
- Energy efficiency: They use solar energy directly and naturally, without the need for additional technological devices. This reduces conventional energy consumption.
- Thermal comfort: Passive systems maintain heat in winter and prevent overheating in summer, all naturally.
- Economic savings: By reducing the use of mechanical and electrical systems, energy consumption costs are significantly reduced.
- Low maintenance: Since they do not employ mechanical elements, passive solar systems require little maintenance.
- Sustainability: By relying solely on solar radiation, these systems do not emit greenhouse gases and contribute to mitigating climate change.
Disadvantages of passive solar systems
Despite the numerous advantages of passive solar systems, there are also Some disadvantages that should be considered before implementing them:
- Dependence on weather conditions: These systems depend on the availability of solar radiation. In places with little sunlight or on cloudy days, their efficiency decreases.
- Limited adaptation to extreme climates: In regions with very cold winters or extremely hot summers, passive systems may not be sufficient on their own and may need support from active technologies.
- Limited power generation: Unlike active solar systems, passive systems do not generate electricity, limiting their use to natural heating and cooling.
How to improve the efficiency of passive solar systems
To maximize the benefits of the passive solar systems, it is essential to pay attention to the architectural design of the building. Some factors that influence its efficiency include:
- Suitable glazing: Windows must be well insulated to prevent heat loss in winter and protect against overheating in summer.
- Use of shadow: Awnings and eaves are effective in preventing excessive heat from entering in summer.
- Construction materials: Using materials with high thermal mass, such as brick or stone, helps store and release heat efficiently.
- Natural ventilation: Designing the building to take advantage of cross ventilation during the warm months is key to maintaining a cool indoor environment.
In summary, passive solar systems represent an excellent option for those looking to improve the energy efficiency of their homes while reducing their environmental impact. With good design and planning, these systems can provide thermal comfort throughout the year, reducing conventional energy use and helping to conserve the environment.